U.S. patent number 4,029,428 [Application Number 05/622,952] was granted by the patent office on 1977-06-14 for pipe repair apparatus.
This patent grant is currently assigned to Nipak, Inc.. Invention is credited to Joseph A. Levens.
United States Patent |
4,029,428 |
Levens |
June 14, 1977 |
Pipe repair apparatus
Abstract
Disclosed is a method and apparatus for repairing a buried main
having connected lateral service conduits. In the method, a main is
opened and cleaned of debris. Thereafter, an elongated conduit
liner is axially inserted into a length of the buried main. The
lateral service conduits are opened and cleaned from a point remote
from their connection to the main. A dispenser is axially inserted
through the service conduit to a point adjacent to the connection.
At the connection, polyurethane material is dispensed into a
portion of the service conduit and in the annular space between the
main and the liner. Thereafter, the dispenser means is removed from
the service conduit and the polyurethane material is allowed to
set. A cutter apparatus is axially inserted into the service
conduit and is manipulated to form a port through the polyurethane
material and the wall of the liner to connect the service conduit
to the liner. Thereafter, a sealer material may be applied to the
exposed polyurethane in the area of the connection. In an
alternative configuration, a conduit liner is axially inserted into
the service conduit to abut the liner of the main. Thereafter,
polyurethane sealant material is injected into the interior of the
service conduit liner at a point adjacent to the liner of the main.
The polyurethane material exits the service conduit liner through
ports formed therein and fills the annular space between the
service liner and the service conduit and the annular space between
the liner of the main and the main. Thereafter, a cutter is axially
inserted into the liner of the service conduit and is manipulated
to form a port through the polyurethane in the service conduit
liner and through the wall of the liner in the main to form a
sealed connection.
Inventors: |
Levens; Joseph A. (Richardson,
TX) |
Assignee: |
Nipak, Inc. (Dallas,
TX)
|
Family
ID: |
27044620 |
Appl.
No.: |
05/622,952 |
Filed: |
October 16, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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474922 |
May 31, 1974 |
3950461 |
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Current U.S.
Class: |
408/127; 408/206;
175/61; 408/225 |
Current CPC
Class: |
F16L
55/179 (20130101); Y10T 408/665 (20150115); Y10T
408/9065 (20150115); Y10T 408/8957 (20150115) |
Current International
Class: |
F16L
55/16 (20060101); F16L 55/179 (20060101); B23B
047/02 (); B29D 027/04 () |
Field of
Search: |
;408/58,59,204,205,206,127,207,209,225,83 ;145/116R,121
;175/61 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
St. Longe, H. S., "Updating Aging Sewers Without Trenching," In
Engineering and Contract Record, July, 1974, pp. 40-44..
|
Primary Examiner: Simpson; Othell M.
Assistant Examiner: Bilinsky; Z. R.
Attorney, Agent or Firm: Richards, Harris & Medlock
Parent Case Text
This is a division of application Ser. No. 474,922, filed May 31,
1974, U.S. Pat. No. 3,950,461.
Claims
I claim:
1. A cutting apparatus for use in interconnecting a relined main
conduit to an intersecting service conduit wherein the main conduit
has a liner positioned therein and wherein the area between the
main conduit and the liner adjacent the intersection of the service
conduit with the main conduit is filled with a foamable setting
resinous material and the area adjacent the intersection of the
service conduit and the main conduit is filled with a foamable
setting resinous material, which comprises:
a cutter having a cylindrical cutting blade substantially
conforming to the shape of said service conduit for forming a
cylindrical opening, and shredding blade means positioned within
said cylindrical cutting blade and axially away from said circular
cutting edge for shredding material within said cylindrical cutting
blade;
a drive shaft with the inner shaft attached to said cutter for
transmitting power to the cutter at a remote location;
means adjacent the cutter for centrally positioning said cutter in
the service conduit;
said positioning means comprising a plurality of lengths of tubing
of a size to surround and axially slide along the exterior of said
drive shaft, a portion extending from the exterior of each of said
lengths of tubing for contacting and sliding along the walls of
said service conduit, each of said extending portions defining an
arcuate radially outward facing surface and having a maximum
outside dimension in the radial direction slightly less than said
service conduit; and
means for reciprocating said cutter within said service conduit
whereby a port is formed between said service conduit and said
liner.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the repair and reconditioning of
buried conduits, such as sewage lines, drainage lines, and the
like. More particularly, the present invention relates to the
repair and reconditioning from a remote location of buried conduit
systems having branching connections between conduits.
In the past, it has been common to use masonry and clay conduits
buried in the ground to construct sewage systems, drainage systems,
and the like. Although these buried conduits have been quite
satisfactory for their purpose, it has been found that over a
period of time, these conduit systems can deteriorate or become
damaged. This deterioration can be as a result of many causes such
as, root action, soil movement, deterioration of the pipe material,
and the like. The conventional method of repairing buried conduit
systems is to completely excavate the system and repair the damaged
portions thereof. The disadvantage of this conventional repair
method is apparent when it is considered that the systems are
commonly positioned under a street or roadway, and are buried in
the ground from 6 to 30 feet. Thus, substantial expenses can be
involved in excavation and repair under these conditions.
In addition, when the systems are located below roadways and other
structures, excavation requires that these structures be disturbed
and repaired. In addition, this method can require substantial
periods of time, and during this time, use of the sewage system and
the roadways is prevented.
To overcome the disadvantages of the excavation method of repairing
and reconstructing buried conduits, a method wherein a flexible
liner of suitable material is axially inserted into the main from a
convenient access point has been used. In this method, a liner can
be pushed through a length of the main to another point where the
access to the main is convenient spanning distances up to 1500 ft.
In some situations, convenient access to the main can be obtained
at existing manholes, or the like. In other situations, excavation
at spaced locations along the length of a sewage main is required.
Once access is obtained, the main is cleaned and lengths of
polyethylene liner can be axially inserted into the main.
This method of inserting a liner has been found to be quite
satisfactory in repairing sections of main which do not have
lateral service conduits connected thereto, but has been
undesirable in repairing systems where a plurality of service
access conduits are connected to and extend from the central main.
This is a result of the fact that heretofore, there was no
satisfactory method for connecting a service conduit to a main at a
remote buried location without additional excavation at the
connection of the service conduit to the main.
Therefore, a great need exists for a method and apparatus of
interconnecting and sealing two conduits of a system at a remote
buried location without excavation at the intersection.
In addition, it is desirable that the connections be made at a
distance of at least 25 feet from the main to eliminate the
necessity of excavating the roadway. It is important that the
resulting connection be leakproof to prevent both infiltration and
exfiltration of the system. The method and apparatus must be able
to work in a dirty, wet environment of systems such as an active
sewer without requiring substantial excavation of or interference
with the use of the roadway. It is desirable that the method be
easy to practice and it is preferable that it be usable in
situations where the lateral service conduit is relined or when the
lateral is not relined. The required equipment must be portable and
adaptable to a wide variety of situations.
Therefore, according to one aspect of the present invention, an
improved method for forming a sealed connection between two
conduits at a remote buried location is provided which can be
performed without the necessity of excavation in the area of the
connection. According to another aspect of the present invention,
improved apparatus are provided for use in forming a sealed
connection between two conduits at a buried remote location.
More particularly, according to the present invention, an improved
method and apparatus is provided for repairing a conduit system,
such as a sewer system, having a buried main and at least one
branching service conduit connected to the main. According to the
improved method, access is gained to the buried main at spaced
locations which are remote from the intersection of the service
line and the main. The service line is also opened at a spaced
location. Thereafter, the main and service line are cleaned. A
length of polyethylene liner is axially inserted into the main
through the area of the connection with the lateral service
conduit. Thereafter, an improved dispenser is axially inserted
through the length of the service conduit to a point adjacent to
the main. A foamable setting resinous material, preferably a
foamable setting synthetic polymer and more preferably a foamable
thermosetting plastic is dispensed in the annulus formed between
the liner and the main in the area of intersection with the service
conduit. Materials which are preferred in the practice of the
present invention include polyurethane foams, acrylamide foams and
elastomer foams with the particular preferred material being
polyurethane foams.
An improved cutter is axially moved through the length of the
service conduit to form a port through the resinous material and
the wall of the liner to connect the service conduit and the liner
of the main. Thereafter, a sealing material can be dispensed in the
area of the connection to coat the resinous material. Thus, a
sealed interconnection is provided.
In another embodiment, the service conduit is also lined with a
polyethylene conduit. The annular spaces between the liners and the
respective service conduit and main is filled with a foamable
setting resin in the area of intersection. Thereafter, a port is
formed in the above-described manner to form a sealed connection
between the two lines.
The advantages and features of the improved method and apparatus of
the present invention will be more readily appreciated by those of
ordinary skill in the art as disclosure thereof is made in the
following description by reference to the accompanying Drawings in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional main buried under a
roadway with branching transverse service conduits connected
thereto;
FIG. 2 is a horizontal section of the buried main at an
intersection with a service conduit showing a liner in place in the
main and the improved dispenser of the present invention in the
service conduit;
FIG. 3 is a vertical section of the buried main taken on line 3--3
of FIG. 2, looking in the direction of the arrows;
FIG. 4 is a view similar to FIG. 3 illustrating the improved cutter
of the present invention in the service conduit;
FIG. 5 is a view similar to FIG. 4 of the connection after the
cutter has removed the material therefrom;
FIG. 6 is a view similar to FIG. 5 illustrating the improved sealer
dispenser dispensing a sealing material onto the exposed resinous
material;
FIG. 7 is a view similar to FIG. 4 of an alternate embodiment of
the present invention illustrating the use of a liner in the
lateral service conduit;
FIG. 8 is a horizontal section of the embodiment illustrated in
FIG. 7 with a port connecting the two liners; and
FIG. 9 is an alternate embodiment of the end structure of a liner
for the service conduit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the Drawings wherein like reference characters
designate like or corresponding parts throughout the several views,
there is illustrated in FIG. 1 a conventional sewage system which
for purposes of description is identified by reference numeral 20.
The sewage system 20 is shown buried in the ground beneath a
roadway 22. The sewage system 20 has a main 24 which is located
under the roadway 22 and are normally 6 to 60 inches in diameter.
The main conduit 24 has a slope of about 2 feet every thousand feet
and can vary in depth in the ground from 6 to 20 feet.
Conventionally, the main 24 is constructed from a plurality of
sections of clay or masonry pipe grouted together as
illustrated.
Lateral branching service conduits 26 are illustrated extended from
the main 24. Each conduit 26 is connected to the main 24 by a "T"
section 28. These service conduits 26 are normally 4 to 8 inches in
diameter and can be constructed from the same material as the main
24. It is to be understood, of course, that in a normal sewage or
drainage system, a plurality of lateral service conduits 26 can
extend from the main conduit 24 at locations spaced along the
length thereof. These service conduits 26 normally extend from
under the roadway 22 to connect residences and commercial
establishments to the system.
The repair and service of the main 24 and the lateral service
conduits 26, if conventionally performed, can require extensive
excavation of the roadway 22 and disruption of the use of the
roadway 22 and system 20. For purposes of illustration, a
deterioration or leak 30 is located in the sewage system 20 under
the roadway 22.
To practice the improved method of the present invention, access to
the main 24 is accomplished through a manhole 29 providing an
access space 31 as shown in FIG. 1. For convenience, the access
space 31 is shown at an intersection providing access to mains 24
under the various roads of the intersection. At a point located
away from the space 31 (not shown), the main 24 is similarly
opened. A typical situation would allow access to the main 24 at
the next intersection or even further along the roadway.
Next, the main 24 is cleaned of roots and other debris by
conventional methods well known in the art. Thereafter, a liner 32
of a suitable material, such as polyvinyl chloride, polybutylene,
polypropylene, polyethylene, or the like, is axially inserted into
the main 24 in the direction of arrow 34. The liner 32 is of
sufficient length to span the distance between the two access
openings for the main. It is also to be understood that the liner
32 extends through the "T" sections 28 and the area of the leak 30.
In the past, liners have been used to span distances up to 1500
feet in length. It is envisioned, of course, that greater lengths
could be spanned, if desired.
The service conduit 26 is next opened at a convenient point. In the
present embodiment, the conduit 26 is excavated at a point 36
spaced away from the roadway 22 and preferably at a point where
conduit 26 is at a minimum depth. This excavation 36 can be spaced
25 ft. or more away from the main 24. In a conventional manner, the
service conduit 26 is cleaned of debris. It is also envisioned that
the service conduit 26 could be cleaned prior to the insertion of
liner 32.
According to an improved feature of the present invention, the
lateral service conduit 26 is connected to the liner 32 without
excavation of the "T" section 28. As illustrated in FIG. 2, the
first step of the improved method involves axially inserting a
flexible dispensing assembly 38 into the open end of the lateral
service conduit 26 in the direction of arrow 42. The assembly 38 is
sufficiently flexible to allow insertion along the length of the
conduit 26. The assembly 38 has an elongated flexible conduit 39
with a seal 40 mounted thereon near the end 43. The seal 40 can be
of any suitable construction which conforms with the interior of
conduit 26. It is envisioned that the seal 40 could be of the
expandable or inflatable type which can be operated to seal against
the interior wall of conduit 26 once the dispenser assembly 38 is
in position. The end 43 is open to dispense material into conduit
26 from conduit 39.
When positioning the assembly 38, the conduit 39 is first inserted
in the open end of conduit 26 until the end 43 of the assembly 38
contacts the wall of the liner 32 at 44, as shown in dotted lines
in FIG. 2. Next, the assembly 38 is moved a set distance in the
reverse direction of arrow 42 to a desired position. The seal 40
can then be actuated.
The external end of conduit 39 is connected to the lower portion of
a cylinder 46. A piston 48 divides the cylinder into upper and
lower variable volume chambers. The piston 48 is free to axially
reciprocate in the cylinder 46 in sliding sealing engagement with
the walls thereof.
The upper end of the cylinder 46 is closed by a removably attached
cap 50. Cap 50 can have suitable means such as threads to allow
removal. A conduit 52 connects the upper chamber of the cylinder 46
with a source of pressurized gas 54. A valve 55 is provided to
regulate the flow of pressurized gas into the upper chamber of the
cylinder 46.
Once the end 43 is in the desired position, the cap 50 and piston
48 are removed from cylinder 46. A settable foaming resinous
sealant material 56 is mixed and placed in the lower chamber of the
cylinder 46. The resinous sealant material 56 is preferably a
foamable setting synthetic polymer and more preferably a foamable
thermosetting plastic. The sealant material should be foamable and
expand upon application to form a compression fit as hereinafter
described. It must be nonsoluble as well as resistant to attack
from the fluids in which it is used. Materials which are preferred
in the practice of the present invention include polyurethane
foams, acrylamide foams and elastomer foams with the particular
preferred material being polyurethane foams.
Piston 48 is placed in the cylinder 46 and the cap 50 is attached.
Thereafter, the valve 55 is manipulated to release pressurized gas
into the upper portion of the cylinder 46 to force the resinous
material 56 to flow through the conduit 39 and to be dispensed from
the end 43. The dispensed material 56 will fill the conduit 26 in
the area 58 and will flow in the direction of arrows 60, as shown
in FIGS. 2 and 3, into the annular space 59 formed between the
liner 32 and fitting 28. This process continues until material 56
occupies the annular space 59 in the area of the intersection of
the service conduit and the main 24. Dotted lines 61 represent the
approximate area which is eventually occupied by the resinous
material. It is to be understood, of course, that the material 56
will foam and expand into the areas 58 and 59 causing a compression
fit between liner 32 and fitting 28. The resinous material is
allowed to set, thus surrounding and sealing the lateral conduit 26
from the main 24. It is also important to note that one face 62 of
the seal 40 is tapered to form an inclined annular shoulder 64 on
the end of area 58. This shoulder 64 assists in preventing flow
blockage at this point.
After the resinous material is set, the dispenser 38 is pulled from
the lateral service conduit 26 and a cutter assembly 70 is axially
inserted into conduit 26 in the direction of arrow 42. This cutter
assembly 70 has a cutting head 72 with a leading bit 73. The head
72 is driven by a flexible shaft 76. The shaft 76 is driven by a
remote power means located at the excavation 36. Centering elements
74 can be provided for the shaft 76 to position the head 72 within
the conduit 26. These centering elements 74 each have a short
length of tubing 80 and an axially extending portion 82 for
contacting the interior walls of conduit 26 to center the shaft 76
and head 72.
The head 72 has a cylindrical sawtooth blade 84 which defines the
periphery of the port formed by head 72. Shredding teeth 86 are
positioned within the blade 84 to shred the resinous material
captured therein during the cutting process.
To connect the service conduit 26 to the liner 32, the cutter
assembly 70 is axially inserted into conduit 26 in the direction of
arrow 42 as shown in FIG. 4. This insertion of assembly 70 is
continued until the head 72 begins to cut into the resinous
material in area 58.
As the head 72 cuts into area 58, the blade 84 will form the wall
of a port 89. The centering structure 74 will insure correct
positioning of the head 72 while the blades 86 will shred the
resinous material in the port 89. Movement of the head 72 in the
direction of arrow 42 is continued until a coupon 78 is cut from
the wall of liner 32 and retained in head 72. The cutter assembly
70 is removed from conduit 26 as shown in FIG. 5, thus removing the
coupon 78 and shredded resinous material 88.
The port 89 is illustrated in FIGS. 5 and 6 and has an annular wall
96 in the area 58. This is due to the fact that the blade 84 is
slightly smaller than the interior diameter of conduit 26. In
addition, the resinous material fills the space 98 between the
liner 32 and conduit 26. Thus, a sealed connection is formed
between conduit 26 and liner 32, without excavating the area of
connection.
A suitable sealing material may be applied to the walls of port 89.
This may be accomplished by using a dispenser swab assembly 90.
This assembly 90 has an elongated conduit 91 which is used to
position a dispenser 94 in conduit 26 and to convey sealing
material thereto. The dispenser 94 has a plurality of openings 92
spaced about the periphery thereof. Thus, the sealing material can
be dispensed through openings 92 onto the walls of port 89. A plug
95 can be provided to prevent any excess sealing material from
entering the liner 32.
An alternate embodiment of the present invention is illustrated in
FIGS. 7 through 8. In this embodiment, the improved process of the
present invention is practiced with the additional step of relining
the lateral service conduit 26. As illustrated in FIG. 7, a liner
132 is inserted into lateral service conduit 26. The liner 132 is
inserted in the manner similar to the liner 32 by axially pushing
the liner into conduit 26 in the direction of arrow 42. It is
important to note that the liner 32 is provided with a plurality of
ports 134 adjacent to end 136. These ports 134 allow the freeflow
of the foamable setting resinous material when it is injected into
the liner 132 as will be hereinafter described. The liner 132 is
inserted into the service conduit 26 until the end 136 contacts
liner 32.
Thereafter, the dispensing assembly 38, previously described, is
inserted into the liner 132. The seal is then actuated and resinous
material is dispensed into the area 138 within the end of liner
132. The resinous material also flows through the ports 134 and
into the annular area 140 defined between the conduit 26 and liner
132 and also into the annular space 59.
Once the dispensing process is complete, the dispenser can be
removed from the liner 132 allowing the resinous material to set.
Thereafter, cutter assembly 70 can be inserted into the liner 132
as shown in FIG. 7. The cutter is manipulated to form a port 142
through the area 138 and the wall of the liner 32. If desirable, a
stop 143 can be fixed on the shaft 76 to limit the axial extension
into the liner 32. This port 142 connects liner 132 and liner 32.
As shown in FIG. 8, the resinous material in area 138 will form a
cylindrical wall 144 within the liner 132 and will seal the space
146 adjacent the intersection of the two liners. Thus, a sealed
interconnection is made between a relined service conduit and
relined main.
It is also envisioned that the previously disclosed sealing step
can be performed in the embodiment illustrated in FIGS. 7 and
8.
An alternate embodiment of the service conduit liner is illustrated
in FIG. 9. This liner 132' has slots 148 formed at the end 136' to
allow the flow of resinous material from the interior of the liner
132 to the exterior thereof during the sealing and joining process.
It is also envisioned that other shapes could be used.
Thus, the present invention teaches an improved method and
apparatus which allows the connection of buried conduits without
the necessity of excavation in the area of the connection. It is
apparent that this process could be repeated as required throughout
the system 20 with excavation being required only for gaining
access to the service conduits. It is also apparent that the
improved method of the present invention could be used to repair
systems having various types and shapes of fittings therein.
It is to be understood, of course, that the foregoing disclosure
relates only to preferred embodiments of the present invention and
that numerous alterations and modifications can be made therein by
those of ordinary skill in the art without departing from the
spirit and scope of the invention as set forth in the appended
claims.
* * * * *